The disclosure relates to the field of suction pumps for dispensing a liquid material, such as soap or alcohol sanitizer or detergent out of a container such as a bottle or the like. In use, the container is interconnected to the pump, and introduced in a dispenser, which is typically fixedly arranged on a wall in a bathroom or the like. Certain dispensers include a non-disposable pump which is integrated with the dispenser, and to which disposable containers may be coupled. Other dispensing systems may include a disposable pump, which may be connected to a disposable container for attachment to a multiple-use dispenser.
In many applications, the liquid is dispensed as a liquid. However, it is sometimes preferred to dispense the liquid as a spray, e.g. in order to cover an area, e.g. spraying soap on a hand. Moreover, dispensing by spraying distributes the liquid better as compared to dispensing as a liquid. It is possible to decrease the amount of liquid used at each dispensing operation as compared to conventional systems dispensing in liquid state.
A vast number of different suction pumps have been proposed in the past for dispensing liquids. Many suction pumps include a pressure chamber, from which a volume of liquid may be dispensed. The liquid leaving the chamber creates a negative pressure in the fluid chamber, which negative pressure functions to draw new liquid from the container into the pressure chamber, which thereby is filled and ready to dispense a new volume of liquid.
However, when dispensing a liquid as a spray, the pressure difference required from the pump is larger than for conventional systems dispensing the liquid in liquid state, since the pressure difference is also utilized to give kinetic energy to the liquid in order to break it up into droplets forming the spray. The process of forming the droplets of the spray is known as atomization.
One type of known dispensers includes an actuation means for activating the pump and dispensing a volume of fluid. Another type of known dispensers is arranged such that a portion of the pump extends out from the dispenser, displaying an actuation means arranged in integrity with the pump. There are generally two kinds of actuation means, whether integrated in the dispenser or in the pump.
One kind is a longitudinally acting actuation means. Longitudinally relates in this context to a direction parallel to the dispensing direction and to a spout of the pump. Pumps for longitudinal actuation often include a slidable piston which may be pushed/pulled in a longitudinal direction for diminishing/expanding the volume inside the pressure chamber of the pump, whereby the pumping effect is created. When the actuation means is formed in integrity with the pump, it may include an outlet for dispensing the liquid.
Another kind of actuation means is a transversely acting actuation means. Transversely relates in this context to a direction transverse to the dispensing direction and transverse to a spout of the pump. Pumps for transversal actuation are typically to be arranged in a fixed dispenser which includes a transversally acting actuation means. The transversally acting actuation means may be a bar or the like, which upon transversal displacement acts to diminish the volume inside the pressure chamber of the pump.
As the pumps, containers are known in a large variety of forms. One particular type of containers is collapsible containers, which are intended to gradually collapse, decreasing their inner volume, as fluid is dispensed therefrom. Collapsible containers are particularly advantageous in view of hygienic considerations, as the integrity of the container is maintained throughout the emptying process, which ensures that no contaminants are introduced thereto, and that any tampering with the content of the container is impossible without visibly damaging the container. Use of collapsible containers involves particular requirements to the pumps. In particular, the suction force created by the pump must be sufficient not only to dispense the liquid, but also to contract the container. Moreover, a negative pressure may be created in the container, striving to expand the container to its original shape. Hence, the pump must be able to overcome also the negative pressure.
One type of collapsible containers is simple bags, generally formed from some soft plastic material. Bags are generally relatively easy to collapse, and the bag walls would not strive to re-expand after collapse, hence the bag walls would not contribute to any negative pressure in the bag.
Another type of collapsible containers has at least one relatively rigid wall, towards which the collapse of the other, less rigid walls of the container will be directed. Hence, hereinafter, this type of container is referred to as a semi-rigid collapsible container. This type of collapsible containers is advantageous in that information may be printed on the rigid wall, such that the information remains clearly visible and undistorted regardless of the state of collapse of the container. Moreover, for some contents, containers having at least one relatively rigid wall may be preferable over bags. However, collapsible containers having at least one relatively rigid wall may require a greater suction force generated from the pump in order to overcome the negative pressure created in the container during emptying thereof than the bags.
For disposable pumps, there is a general desire that the pump should be relatively easy and economical to manufacture. Moreover, it is advantageous if the pump includes materials that may easily be recycled after disposal and even more advantageous if the pump may be recycled as a single unit without need of separating its parts after disposal.